Bug 28331

Summary: screen flickers all the time with desktop image appearing only briefly
Product: DRI Reporter: Gildas Le Nadan <3ntr0p13>
Component: DRM/RadeonAssignee: Default DRI bug account <dri-devel>
Status: RESOLVED FIXED QA Contact:
Severity: critical    
Priority: medium    
Version: unspecified   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
Xorg.0.log
none
dmesg
none
avivotool dumps with kms (v2.6.34)
none
avivotool dumps with ums (v2.6.34 radeon.modeset=0)
none
possible fix none

Description Gildas Le Nadan 2010-05-31 08:45:53 UTC
Created attachment 35972 [details] [review]
Xorg.0.log

Machine is an Acer Aspire L5100 with an AMD Athlon 64 X2 Dual Core Processor 4000+ running a 64 bits debian sid.

The machine is a small factor desktop machine designed around laptop components, so the graphic card is an integrated radeon x1200.

When running a linux vanilla kernel 2.6.34, the screen flickers all the time making the machine unusable, while with kernel 2.6.33 such "flick to black" event occured from time to time but most of the time the desktop was correctly displayed.

radeon.new_pll=0 doesn't solve the problem
radeon.nomodeset=0 does

The problem was bisected to commit 383be5d1789d9a7a2e77dca1cb0aca89507d069e

The following packages version are installed:
xserver-xorg                           1:7.5+6
xserver-xorg-core                      2:1.7.7-1
xserver-xorg-video-radeon              1:6.13.0-2

Please find attached Xorg.0.log and dmesg for that machine (when booted on 2.6.34 with no radeon option).
Comment 1 Gildas Le Nadan 2010-05-31 08:46:24 UTC
Created attachment 35973 [details]
dmesg
Comment 2 Alex Deucher 2010-06-01 22:14:15 UTC
Can you dump the following regs using avivotool in both kms and ums?  You can get avivotool here:
http://cgit.freedesktop.org/~airlied/radeontool/
and most distros package it.
e.g.,
avivotool regmatch 0x0400 >> kms.out
avivotool regmatch 0x0404 >> kms.out
avivotool regmatch 0x0430 >> kms.out
avivotool regmatch 0x0438 >> kms.out
avivotool regmatch 0x043c >> kms.out
avivotool regmatch 0x0450 >> kms.out
avivotool regmatch 0x0410 >> kms.out
avivotool regmatch 0x0414 >> kms.out
avivotool regmatch 0x0434 >> kms.out
avivotool regmatch 0x0440 >> kms.out
avivotool regmatch 0x0444 >> kms.out
avivotool regmatch 0x0454 >> kms.out
Comment 3 Gildas Le Nadan 2010-06-02 03:30:59 UTC
Created attachment 36005 [details]
avivotool dumps with kms (v2.6.34)
Comment 4 Gildas Le Nadan 2010-06-02 03:34:28 UTC
Created attachment 36006 [details]
avivotool dumps with ums (v2.6.34 radeon.modeset=0)
Comment 5 Alex Deucher 2010-06-08 14:44:01 UTC
Created attachment 36167 [details] [review]
possible fix

Does this drm kernel patch help?
Comment 6 Gildas Le Nadan 2010-06-08 16:36:50 UTC
Thanks Alex: I applied the patch on top of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git and it seems to fix the "flicker all the time issue" for me.
Comment 7 Alex Deucher 2010-06-08 16:45:15 UTC
I've sent it to Dave for inclusion in the kernel.

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